USB 2.0 –A widely used standard that offers a maximum transfer speed of 480 Mbps. USB 3.0/3.1/3.2 –Offer transfer speeds of up to 5 Gbps (USB 3.0), 10 Gbps (USB 3.1), and 20 Gbps (USB 3.2). These are backward compatible with USB 2.0 devices but might reduce the overall transfer speed when a USB 2.0 device is connected.